In a power transmission device for a vehicle, a transmission clutch is interposed between an engine and a transmission (see, for example, Japanese Patent Application Laid-Open No. H6-147303 and Japanese Patent Application Laid-Open No. H10-122352).
In such a power transmission device, control is performed to determine whether there is an engine stall risk (in other words, whether the engine has abruptly decelerated) on the basis of an engine operation state such as engine revolution speed. When the determination is affirmed, the transmission clutch is disconnected and a load, from the drive wheel side of the engine, is cut off from the transmission.